A Hybrid Decision-Making Model for Optimal Portfolio Selection under Interval Uncertainty

This paper proposes a hybrid approach that integrates fuzzy multi-criteria decision-making with multi-objective mathematical optimization to address the investment management problem in the Iranian capital market under interval uncertainty. To achieve this, we first employ the fuzzy SWARA method to assess the global importance of the criteria weights. Subsequently, we develop a fuzzy EDAS method to rank the active industries in the Iranian capital market, including basic metals, chemical products, investment services, metal ore mining, financing, insurance, pension funds, and social security. Next, we present a mathematical model to determine the optimal investment amount for each ranked alternative. According to the numerical results, the most critical criteria for evaluating different investment areas are access to financial resources, distribution networks, and raw materials. The highest optimal share of investment is associated with Fars 1, while the lowest value pertains to Gharn 1. When solving the model under conditions of uncertainty, we observe that increasing parameter from small to large values decreases the value of the first objective function for the most efficient Pareto member. However, when exceeds 10, the value of the first objective function stabilizes. Additionally, the third objective function shows an increasing trend as the parameter decreases. The results obtained can serve as a managerial tool for stakeholders involved in research participation.